The presence in a dense urban area of such a big reptile—a species notoriously vulnerable to being killed by speeding vehicles—can teach us something about making our growing cities friendlier for wildlife.

Happily, such efforts make cities better for people too. By 2100, there are projected to be around 11 billion people on Earth—of which an incredible 9 billion will be living in cities.

CITIES CAN SUSTAIN BIODIVERSITY

A surprising amount of biodiversity can persist among the skyscrapers, housing estates, shopping malls, parks, and greenbelts that constitute our modern cities.

Even some vanishingly rare species can use cities. Imperiled plants have been discovered in weedy abandoned lots, endangered snails in irrigation pipes.

In northern Queensland, Australia, critically endangered Cassowaries regularly enter homeowners' back yards looking for fruiting plants, so long as dogs are not present.

And native wildlife can have many benefits, such as limiting pest outbreaks and major disease-vectors like mosquitoes and rats.

Beyond all this, we know that appreciating nature is something people have to learn. Exposing children in cities to nature—not just animals on TV or video games—is one of the best strategies for educating them about the vital need to make our world more sustainable.

CITIES FOR THE FUTURE

The bottom line: We all have a big stake in making our burgeoning cities friendlier for nature.

Just ask that big python on Cannon Racetrack in Cairns, Australia—which the jockey and his galloping horse happily managed to miss.

Though in the middle of a city, the racetrack is encircled by trees, and wallabies and other wildlife that the snake would feed on are protected and plentiful.

The snake was obviously happy on the racetrack—it sun-baked there for four hours.